Discovery · 1610 CE
The Phases of Venus
History of Astronomy
Overview
Galileo observed that Venus shows a full cycle of phases like the Moon, including a 'full' phase only possible if it orbits the Sun.
Why it matters
Among the strongest observational evidence for the heliocentric model.
Credit
Objects & facilities
Bearing on theory
Knowledge connections
- Discovered byGalileo Galilei
- Part ofThe Scientific Revolution
- Related toVenus
- ConfirmedThe Heliocentric Model
- RefutedThe Geocentric Model
Sources & references
The primary and reference sources this topic draws on.
- BritannicaEncyclopaedia Britannica
General reference for the history of astronomy, biographies, and cultural context.
- NASANational Aeronautics and Space Administration
Mission data, planetary science, space telescopes, and public-domain imagery.
Most NASA-produced imagery is in the public domain; individual items are checked for usage terms before publication.